Atrial natriuretic peptide during the elevation in blood pressure induced by sodium restriction.

This study examined the effects of dietary sodium restriction combined with unilateral nephrectomy on systolic blood pressure (SBP), heart rate, plasma renin activity (PRA) and immunoreactive atrial natriuretic peptide (iANP) in the conscious rat. SBP and heart rate, measured by photoelectric tail-cuff, were elevated in both one- and two-kidney, sodium-restricted rats compared with one- and two-kidney rats maintained on a normal-sodium intake. In addition, the SBP of one-kidney, low-sodium rats was significantly elevated compared with two-kidney, low-sodium rats on days 10 and 14 postnephrectomy. PRA was significantly elevated two- to threefold in one- and two-kidney, low-sodium rats compared with rats fed the normal-sodium chow. Plasma iANP levels in rats fed the normal-sodium diet averaged 291 +/- 45 and 277 +/- 35 pg/ml in one- and two-kidney rats, respectively. Plasma iANP levels were significantly lower in the one- and two-kidney, low-sodium rats and averaged 165 +/- 15 and 182 +/- 22 pg/ml, respectively. These results indicate that dietary sodium restriction can elevate blood pressure in the rat and that this response can be augmented by unilateral nephrectomy. In addition, the exacerbation of the hypertension by unilateral nephrectomy in sodium-restricted rats is not attributable to differences in PRA or plasma levels of iANP between one- and two-kidney, sodium-restricted rats.

A comparison of three health status indicators.

Interest in health status indicators has produced measures of widely varying applicability. We were interested in the use of such indices to establish mean recovery curves for groups of similar patients undergoing acute hospital treatment. A longitudinal study relating resource usage to these recovery curves had been intended but there were difficulties in finding suitable indicators. Firstly, two published indicators relying on patient interviews were tested for consistency. Poor correlations were found among those scorers unfamiliar with the patients and it seems unlikely that these indicators could be used in a routine system. Different parts of the indices presented difficulties to the different professions involved in scoring, and a multidisciplinary approach may be needed in assessing full health. The indicators tested included no assessment of prognosis. Those parts of the indices which had produced significant correlations were retained in subsequent work and were supplemented by further measures designed to overcome the earlier difficulties. A new trial of this indicator was undertaken where staff, familiar with the patients, scored data recorded by the Problem Oriented Medical Record system. This produced improved correlations but some problems remain.